A fair number of shops carry it, especially online. So, its pretty east to find or you can order direct from Mason.

I generally use either 20 or 25 lb. test for weed guards. The stuff is so stiff you probably don't want to go any heavier than that. Its stiff to the point that above a certain thickness, it has a tendency to reduce hookups with fish (bass anyway, I don't imagine it matters much to pike or muskies) as well as deter fouling by weeds.

tossing a large hopper over weed infested structure to the shore, then a hard jerk of the line to simulate it hopping off the shore into the water works great. also check out this guys "Chickenbats" i have had great luck with them for LMB's and giant striped bass in TX and OK